Physical Fitness and Body Composition of Youth Referees in Invasion Games

Background: Referees’ activity can be an instrument for training students with an impact on health-related physical fitness (PF). This study aimed to investigate the differences in PF and body composition between students without sports practice (G1), students with regular sports practice (G2), and student referees in team invasion games (G3). Methods: This study followed a cross-sectional design. The sample comprised 45 male students between 14 and 20 years old (16.40 ± 1.85). Three groups (G1, G2, and G3) of 15 participants each were selected. PF was assessed by a 20 m shuttle run, change-of-direction test, and standing long jump. Body composition was determined by body mass index (BMI; kg/m2) and the percentage of body fat (%BF) predicted by skinfold. Results: After controlling for age as a covariate, the block of variables used to characterize PF was statistically different between sports practice groups favoring student referees (p < 0.001; r = 0.26). Similar results were achieved for body composition (i.e., BMI and %BF) (p < 0.001; r = 0.17). However, when the dependent variables were evaluated separately, there were only differences between groups in %BF (p = 0.007; r = 0.21). Student referees had statistically significantly lower values than the remaining groups. Conclusion: Refereeing activity benefits PF related to health and performance, including body composition. This study confirms the benefits related to health in children and adolescents who are involved in refereeing activity.

Changes in Estimated Body Composition and Physical Fitness of Adolescent Boys after One Year of Soccer Training

Sports participation is one of the most popular forms of physical activity among youngsters. This study aimed to examine the changes in the estimated body composition, strength, and flexibility of adolescent boys after 12 months of soccer training compared with those of age-matched controls with non-sports participation. We assessed 137 boys (62 soccer players and 75 controls) at baseline (TM1) and 12 months later (TM2). The differences in estimated body composition, strength, and flexibility were investigated using a repeated measure analysis of variance. The analysis revealed a significant main effect of soccer training on fat mass (F = 73.503, p ≤ 0.01, η2 = 0.59) and fat-free mass (F = 39.123, p ≤ 0.01, η2 = 0.48). Over time, the soccer group decreased their fat mass and increased their fat-free mass, while the opposite results were observed for the controls. Among physical fitness tests, a substantial effect of soccer training was evidenced for the sit-up performance (F = 16.224, p ≤ 0.01, η2 = 0.32). Regarding the time factor, significant effects were noted for height and handgrip strength. No significant differences were detected for flexibility. Overall, the benefits of soccer training were exhibited by the larger improvements in fat mass, fat-free mass, sit-ups, and handgrip strength performance, underlining the important role of soccer participation during adolescence.

School-Based Family-Oriented Health Interventions to Promote Physical Activity in Children and Adolescents: A Systematic Review

OBJECTIVE

This study aimed to systematically review and analyse intervention programs in a school context centred on the family, focused on increasing youths' physical activity.

DATA SOURCE

The research was carried out in the PubMed, Scopus and Web of Science databases.

STUDY INCLUSION CRITERIA

Studies were included if participants were children or adolescents, focusing on school-based intervention studies with parental involvement and physical activity, sedentary behaviour or physical fitness outcomes.

DATA EXTRACTION

The search was performed according to the PRISMA protocol. A total of 416 articles were identified. After being considered for eligibility and duplicates, 22 studies were identified as relevant for inclusion.

DATA SYNTHESIS

Sample and intervention characteristics, objective, the role of the family, outcomes measures, main findings regarding the outcomes and risk of bias.

RESULTS

Ten studies reported improvements in physical activity, 6 in sedentary behaviour and 9 in the components of physical fitness and/or skills related to healthy behaviours and lifestyles. Most of the interventions adopted a multidisciplinary and multi-component approach.

CONCLUSIONS

Most interventions employed a school's multidisciplinary/multi-component approach to promoting physical activity, nutrition, and general education for healthier lifestyle behaviours. The impact of school-based interventions involving families on youth's physical activity levels is still a relatively emerging theme. Further research is needed given the diversity of the intervention's characteristics and the disparity in the results' efficacy.

Body Composition and Physical Fitness in Madeira Youth

BACKGROUND

Research on composition and physical fitness is lacking in school-aged children from Madeira. This study aimed to examine the frequencies of overweight and obese participants and, in addition, to compare the fitness levels of Madeira youth with reference data.

METHODS

The sample comprised 521 participants (n = 258 boys; n = 263 girls) aged 10.0-18.9 years old.

METHODS

Height and weight were measured. Body mass index (BMI) was calculated, and percent fat was derived from skinfolds. Tests detailed on FITESCOLA battery were performed. BMI was plotted against U.S. reference data and physical assessment contrasted with the cut-off points of FITESCOLA protocol and corresponding data developed in Portuguese youth.

RESULTS

The percentages of overweight and obesity were 15% (overweight) and 14% (obesity) for boys and 16% (overweight) and 6% (obesity) for girls. The median values of fat mass percentage were closely related to the cut-off standards; however, substantial variation was noted. Boys and girls tended to be below the recommendations of cardiorespiratory fitness.

CONCLUSIONS

Sport participation should be promoted in Madeira to attain acceptable values of body composition and physical fitness levels.

Association between the Duration of the Active Commuting to and from School, and Cognitive Performance in Urban Portuguese Adolescents

This study aimed to analyze the differences between active commuting to school (ACS) and non-ACS in cognitive performance (CP), and the association of ACS duration with CP. This cross-sectional study included 370 adolescents (males n = 170), with a mean age of 15.28 ± 2.25 years. CP was assessed through an interview, and ACS, extracurricular physical activity, and socioeconomic status was assessed by self-report. Body composition was assessed using the FitnessGram test battery. One in two adolescents did ACS (51.6%). ACS was associated with boys (53.9%), younger adolescents (14.91 ± 2.15 vs. 15.69 ± 2.29), those having school social support (55.0%), and those doing one or more extracurricular physical activities (53.6%), compared to non-ACS participants (p < 0.05). The analysis of covariance, after controlling for age, sex, school social support, and participation in extracurricular physical activity, showed an effect of ACS on the total cognitive score (F_(2,362) = 3.304, p < 0.05). The CP was higher in adolescents with more than 30 min of ACS than non-ACS (p < 0.05). The influence of ACS duration can be seen in the dimensions of inductive reasoning (ß = 0.134, t = 2.587, p < 0.05) and working memory (ß = 0.130, t = 2.525, p < 0.05). The role of ACS for CP, as well as guidelines for future research, are discussed.

Sports Injuries of a Portuguese Professional Football Team during Three Consecutive Seasons

Professional football players are exposed to high injury risk due to the physical demands of this sport. The purpose of this study was to characterize the injuries of a professional football team in the First Portuguese League over three consecutive sports seasons. Seventy-one male professional football players in the First Portuguese Football League were followed throughout the sports seasons of 2019/2020, 2020/2021, and 2021/2022. In total, 84 injuries were recorded. Each player missed an average of 16.6 days per injury. Lower limbs were massively affected by injuries across all three seasons, mainly with muscular injuries in the quadriceps and hamstrings and sprains in the tibiotarsal structure. Overall, the injury incidence was considerably higher in matches than in training. The two times of the season that proved most conducive to injuries were the months of July and January. Our results emphasize the importance of monitoring sports performance, including injury occurrence, and assisting in identifying risk factors in professional football. Designing individualized training programs and optimizing prevention and recovery protocols are crucial for maximizing this global process.

Playing 7 vs. 6 with an empty goal: Is it really an option for coaches? A comparative analysis between Portugal and the other teams during the Men’s European Handball Championship 2020

The dynamic of changes in the rules in team games materialize from research and debate between experts and coaches before being implemented by the International Federations. In Handball, the last changes occurred in 2016, and one of them was to substitute the goalkeeper with an additional field player allowing teams to play “empty goal” while using the additional field player.

This study aimed to analyze and characterize the use of the 7 vs. 6 strategical-tactical option for the attack in the 2020 Men’s European Championship. We also analyzed whether the game time and partial score influenced the use of 7 vs. 6 and its efficiency. Observational methodology and a mixed ad hoc instrument combining field format and category systems validated by experts were used. Data were taken from 28 matches involving teams in the first 12 positions in the 2020 Men’s European Championship. The total number of offensive sequences in an organized attack method in 7 vs. 6 with an empty goal (n = 123) were analyzed. Sequential analysis techniques with lags, prospective and retrospective, and polar coordinate analysis were used. The results showed that (a) these solutions had poor efficiency, except for the Portuguese National Team; (b) teams using the 7 vs. 6 tactic option had no negative consequences or increased risk with the opponent response; (c) partial score influenced the decision to use 7 vs. 6 strategic option, and (d) game time was associated with 7 vs. 6 play options and detected patterns.

Predictive Modeling of Injury Risk Based on Body Composition and Selected Physical Fitness Tests for Elite Football Players

Injuries are one of the most significant issues for elite football players. Consequently, elite football clubs have been consistently interested in having practical, interpretable, and usable models as decision-making support for technical staff. This study aimed to analyze predictive modeling of injury risk based on body composition variables and selected physical fitness tests for elite football players through a sports season. The sample comprised 36 male elite football players who competed in the First Portuguese Soccer League in the 2020/2021 season. The models were calculated based on 22 independent variables that included players' information, body composition, physical fitness, and one dependent variable, the number of injuries per season. In the net elastic analysis, the variables that best predicted injury risk were sectorial positions (defensive and forward), body height, sit-and-reach performance, 1 min number of push-ups, handgrip strength, and 35 m linear speed. This study considered multiple-input single-output regression-type models. The analysis showed that the most accurate model presented in this work generates an error of RMSE = 0.591. Our approach opens a novel perspective for injury prevention and training monitorization. Nevertheless, more studies are needed to identify risk factors associated with injury prediction in elite soccer players, as this is a rising topic that requires several analyses performed in different contexts.

The Relationship between Different Large-Sided Games and Official Matches on Professional Football Players' Locomotor Intensity

Large-sided games (LSG) are commonly used in the training contexts for providing either technical/tactical or locomotor/physiological stimuli. Despite natural similarities with the official match, the locomotor profile seems to be different, which must be considered by the coaches to identify compensatory strategies for achieving the ideal dose of training. The aim of this study was two-fold: (1) to investigate the locomotor demands imposed by LSGs and the official matches; and (2) to compare the effect of different pitch sizes’ LSG conditions in the locomotor demands. This study followed an observational design. Sixteen professional football players from the same team (26.3 ± 3.0 years old) were included. The study was conducted over four weeks. The same GK + 10 × 10 + GK play format with different pitch sizes (i.e., area per player ranging between 195 m2 to 291 m2) was analyzed. Three official matches were also collected in which the 10 most demanding minutes were considered for further comparisons. Only the same players who participated in matches were considered in comparison with the LSG. The data were obtained using a 10-Hz global positioning system technology. Total distance (TD) and mechanical work (MW) scores increased 20% and 23%, respectively, between the smallest and biggest pitch sizes (p < 0.001). There was a significant difference in locomotor intensity metrics between opponents from different positions on the table (p = 0.001). The biggest LSG (i.e., 291 m2 per player) was the only one that required similar levels of locomotor intensity as required in the official full match. The present study demonstrates that LSG pitch size variation requires different locomotor intensities. Bigger pitch sizes cause an increase in TD and MW. In addition, considering the position on the table, the level of opponents induces different TD covered. Finally, the largest LSG simulates the official match more accurately.

Modelling public health policies for influenza vaccination campaigns

Issue/problem

Public health policies (PHP) are crucial for controlling infectious diseases. Namely, those focused on influenza stand out for the permanent threat of seasonal and the risk of pandemic flu. The COVID-19 pandemic revealed many frailties in PHP, part of which may be lessons to improving responses to future flu epidemics and pandemics. Among the tools available to control influenza, vaccination stands out, a matter where much remains to be improved regarding PHP and communication with the public, among others. The Kassianos model (2021) seeks to create a qualitative conceptual tool to optimizing influenza vaccination campaigns, being organized into 5 pillars with 42 categories.

Description of the problem

We seek to take a step forward based on the Kassianos model, making it quantitative. This project is the mathematical modelling and the testing in a country (Sweden). It started in January 2021 and will be completed towards the end of the year.

Results

This work will allow health authorities and similar partners to have a tool to support the optimization of influenza vaccination campaigns in effectiveness and efficiency. The work is expected to be pre-completed in October 2021. The international presentation of results is intended to be simultaneous at the European Parliament and, if possible, at the 14th European Public Health Conference 2021. The results will cover the dimensions of vaccination and relations to VCR:

Campaign accountability

Access to vaccination

HCP engagement

Burden of Disease Awareness

Communication with the public

Lessons

It is possible to increase the effectiveness and efficiency of vaccination campaigns through the quantitative modelling of aspects related to influenza vaccination, usually worked as qualitative.

Key messages

It is essential to have PHP as rigorous for supporting public health action.

The need for really effective influenza vaccination is critical and must be achieved in the shortest time.

Model-guided development of an evolutionarily stable yeast chassis

First-principle metabolic modelling holds potential for designing microbial chassis that are resilient against phenotype reversal due to adaptive mutations. Yet, the theory of model-based chassis design has rarely been put to rigorous experimental test. Here, we report the development of Saccharomyces cerevisiae chassis strains for dicarboxylic acid production using genome-scale metabolic modelling. The chassis strains, albeit geared for higher flux towards succinate, fumarate and malate, do not appreciably secrete these metabolites. As predicted by the model, introducing product-specific TCA cycle disruptions resulted in the secretion of the corresponding acid. Adaptive laboratory evolution further improved production of succinate and fumarate, demonstrating the evolutionary robustness of the engineered cells. In the case of malate, multi-omics analysis revealed a flux bypass at peroxisomal malate dehydrogenase that was missing in the yeast metabolic model. In all three cases, flux balance analysis integrating transcriptomics, proteomics and metabolomics data confirmed the flux re-routing predicted by the model. Taken together, our modelling and experimental results have implications for the computer-aided design of microbial cell factories.

Face-to-face Assessment of COGTEL in Adolescents: Test-Retest Reliability and Association with School Grades

The Cognitive Telephone Screening Instrument (COGTEL) has shown to be a brief, reliable, and valid instrument to assess cognitive functioning in adults in face-to-face procedures as well as over the phone. So far, no psychometric evaluation exists on its use in adolescents. The present study set out to evaluate the psychometric properties of the face-to-face application of the COGTEL in adolescents in the school context and to analyse the association with school grades. We assessed cognitive performance using COGTEL in face-to-face assessments of 170 adolescents, with retests after 6 months for test-retest reliability. Predictive validity was assessed using school grades. Test-retest reliability for the COGTEL was good (ICC = .77; p < .001). The partial correlation controlling for age between COGTEL and school grades was medium and positive (r = .40; p < .001). School grades alone explained 42% and 36% of the variance in the COGTEL total score in elementary and secondary students, respectively. The present study suggests that COGTEL is a reliable and valid instrument to assess cognitive functioning in adolescents, with the advantage of feasibility in multiple contexts.

Genome-scale modeling of yeast: chronology, applications and critical perspectives

Over the last 15 years, several genome-scale metabolic models (GSMMs) were developed for different yeast species, aiding both the elucidation of new biological processes and the shift toward a bio-based economy, through the design of in silico inspired cell factories. Here, an historical perspective of the GSMMs built over time for several yeast species is presented and the main inheritance patterns among the metabolic reconstructions are highlighted. We additionally provide a critical perspective on the overall genome-scale modeling procedure, underlining incomplete model validation and evaluation approaches and the quest for the integration of regulatory and kinetic information into yeast GSMMs. A summary of experimentally validated model-based metabolic engineering applications of yeast species is further emphasized, while the main challenges and future perspectives for the field are finally addressed.

Adding value to gasification and co-pyrolysis chars as removal agents of Cr3

The present work aims to assess the efficiency of chars, obtained from the gasification and co-pyrolysis of rice wastes, as adsorbents of Cr³⁺ from aqueous solution. GC and PC chars, produced in the gasification and co-pyrolysis, respectively, of rice husk and polyethylene were studied. Cr³⁺ removal assays were optimised for the initial pH value, adsorbent mass, contact time and Cr³⁺ initial concentration. GC showed a better performance than PC with about 100% Cr³⁺ removal, due to the pH increase that caused Cr precipitation. Under pH conditions in which the adsorption prevailed (pH<5.5), GC presented the highest uptake capacity (21.1mg Cr³⁺ g^-1 char) for the following initial conditions: 50mg Cr³⁺ L^-1; pH 5; contact time: 24h;L/S ratio: 1000mLg^-1. The pseudo-second order kinetic model showed the best adjustment to GC experimental data. Both the first and second order kinetic models fitted well to PC experimental data. The ion exchange was the dominant phenomenon on the Cr³⁺ adsorption by GC sample. Also, this char significantly reduced the ecotoxicity of Cr³⁺ solutions for the bacterium Vibrio fischeri. GC char proved to be an efficient material to remove Cr³⁺ from aqueous solution, without the need for further activation.

Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials

The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing.

Removal of phosphorus from wastewaters by biomass ashes

Removal batch assays of phosphates from a synthetic wastewater (SWW) and a pulp and paper mill wastewater (PPWW) with two forestry biomass ashes were performed. The supernatants were not only chemically characterized but also the ecotoxicity was determined using two organisms: Vibrio fischeri and Artemia franciscana. The addition of fly ash and bottom ash to the SWW in solid/liquid (S/L) ratios of 3.35 and 9.05 g L(-1), respectively, achieved removal percentages of phosphates >97% for both ashes. The addition of fly ash and bottom ash to the PPWW in S/L ratios of 34.45 and 46.59 g L(-1), respectively, yield removal percentages of phosphates >90% for both ashes. According to the results of the Langmuir and Freundlich isotherms, the removal of phosphates from the SWW was mainly explained by surface removal mechanisms, while the removal from the PPWW was partially explained by multi-layer mechanisms. The supernatants resulting from the treatment of SWW and PPWW with both biomass ashes did not present acute ecotoxicity.

Physico-chemical properties of chars obtained in the co-pyrolysis of waste mixtures

The present work aims to perform a multistep upgrading of chars obtained in the co-pyrolysis of PE, PP and PS plastic wastes, pine biomass and used tires. The quality of the upgraded chars was evaluated by measuring some of their physico-chemical properties in order to assess their valorisation as adsorbents' precursors. The crude chars were submitted to a sequential solvent extraction with organic solvents of increasing polarity (hexane, mixture 1:1 v/v hexane:acetone and acetone) followed by an acidic demineralization procedure with 1M HCl solution. The results obtained showed that the upgrading treatment allow the recovery of 63-81% of the pyrolysis oils trapped in the crude chars and a reduction in the char's ash content in the range of 64-86%. The textural and adsorption properties of the upgraded chars were evaluated and the results indicate that the chars are mainly mesoporous and macroporous materials, with adsorption capacities in the range of 3.59-22.2 mg/g for the methylene blue dye. The upgrading treatment allowed to obtain carbonaceous materials with quality to be reused as adsorbents or as precursors for activated carbon.

[Methotrexate to treat SAPHO syndrome with keloidal scars]

SAPHO syndrome is an uncommon clinical entity, recently described in literature, which usually affects children, young adults and middle-aged people. It is defined by the association of skin lesions (severe acne, palmo-plantar pustulosis, supurative hidradenitis), synovitis, hiperosthosis and osteitis; however, not all manifestations are required for correct diagnosis. We report a currently forty-two year-old man who initiated follow-up in 1992 for severe acne. His diagnosis changed along the years and has been treated with antibiotics many times to control pustule formation and hidrosadenitis, which evolved to keloidal scars, requiring neck zethaplasty due to limitation of mobility. In 1996 isotretinoin was started, with good response to treatment but recurrence after its completion. Ten years later, isotretinoin was being used again due to worsening clinical picture when the patient developed polyarthritis, lost 11kg in 3 months and was found to have an elevated erythrocyte sedimentation rate. SAPHO syndrome was then diagnosed by the Rheumatology clinic, which started methotrexate at 10mg per week to a good clinical response. Several cutaneous and articular flares have occurred since, however he is now clinically stable with methotrexate 20mg per week and finasteride 5mg per day. SAPHO syndrome is a rare disease and its diagnosis is often late and difficult. In this case, skin lesions preceded arthritis in several years and have been resistant to other common treatments. The patient had a better improve after initiation of methotrexate. Although the skin disease has evolved to keloids, the patient has had excellent treatment response.

Inflammatory bowel disease: a patient's and caregiver's perspective

The purpose of this study was to conduct a survey examining the impact of inflammatory bowel disease (IBD) on patients' and their caregivers' daily activities. Questionnaires were distributed to patients registered in the APDI (Portuguese Association for IBD) database and their respective caregivers in 2007. Of 422 patient respondents, 251 had Crohn's disease (CD) and 171 had ulcerative colitis (UC), with the majority of patients being women (58.1%) and aged over 40 years (37.4%). The number of disease flares experienced by IBD patients was slightly higher for patients with CD than for patients with UC (2.64 vs. 2.34), and surgery was more often required in CD patients as compared to UC patients (42.4 vs. 7%). Sixty percent (60%) of patients reported having no problems with mobility, daily activities, or personal hygiene; however, over half of all patients experienced some pain and anxiety. Adult patients and children and adolescents respectively experienced time off work or school due to their disease but caregivers were not affected in this regard. The caregivers life (N=324) was affected by anxiety, with the major concern reported as the risk of the patient developing cancer. Both IBD patients and caregivers thought that the provision of information on new drugs and contact time with a doctor would have the biggest impact on improving care. The symptoms and complications of IBD have a considerable impact on the lives of patients and their caregivers, and several actions could be taken to improve their care.

[Occult intrasacral meningocele: case report]

Intrasacral meningoceles are rare conditions that can cause symptoms of nerve root compression. We report a case of a 18-year-old female, who presented with urinary incontinence. The neurological and urological evaluation revealed lack of detrusor muscle reflex. This finding supported the hypothesis of spinal disraphism. Magnetic resonance image revealed an intrasacral meningocele. The patient was submitted to surgical excision of the lesion without postoperative complications. In the present paper, the pathogenesis, clinical picture, neuroradiological findings and surgical treatment are discussed.

Kinetics of inter- and intramolecular electron transfer of Pseudomonas nautica cytochrome cd1 nitrite reductase: regulation of the NO-bound end product

The intermolecular electron transfer kinetics between nitrite reductase (NiR, cytochrome cd1) isolated from Pseudomonas nautica and three cytochromes c isolated from the same strain, as well as the intramolecular electron transfer between NiR heme c and NiR heme d1, were investigated by cyclic voltammetry. All cytochromes (cytochrome c552, cytochrome c553 and cytochrome C553(548)) exhibited well-behaved electrochemistry. The individual diffusion coefficients and mid-point redox potentials were determined. Under the experimental conditions, only cytochrome c552 established a rapid electron transfer with NiR. At acidic pH, the intermolecular electron transfer (cytochrome c(552red)-->NiR heme cox) is a second-order reaction with a rate constant (k2) of 4.1+/-0.1x10(5) M(-1) s(-1) (pH=6.3 and 100 mM NaCl). Under these conditions, the intermolecular reaction represents the rate-limiting step. A minimum estimate of 33 s(-1) could be determined for the first-order rate constant (k1) of the intramolecular electron transfer reaction NiR heme c(red)-->NiR heme d1ox. The pH dependence of k2 values was investigated at pH values ranging from 5.8 to 8.0. When the pH is progressively shifted towards basic values, the rate constant of the intramolecular electron transfer reaction NiR heme c(red)-->NiR heme d1ox decreases gradually to a point where it becomes rate limiting. At pH 8.0 we determined a value of 1.4+/-0.7 s(-1), corresponding to a k2 value of 2.2+/-1.1x10(4) M(-1) s(-1) for the intermolecular step. The physiological relevance of these results is discussed with a particular emphasis on the proposed mechanism of "dead-end product" formation.

Neurohumoral behavior in recipients of cardiac pacemakers controlled by a closed-loop autonomic nervous system-driven sensor

The purpose of a sensor-driven pacing system is to physiologically correct chronotropic incompetence (CI). The aim of this study was to evaluate the changes in heart rate provided by a sympathetically driven pacemaker (PM) compared with normal sinus function (NSF). Nine men and six women (age 37-80 years) with AV block and a PM controlled by a closed-loop system were studied. Group I included eight patients with CI, and group II included seven patients with NSF. All patients underwent Valsalva maneuver and tilt table testing with measurements of plasma catecholamines and renin activity. Pacing was initially programmed in the DDDC mode at a lower rate (60 ppm) and upper rate limit (0.85 x [220 - age]), then in DDDR in group I and VVIR in group II. The second phase of the study consisted of nitroglycerin and phenylephrine infusions, and the third phase of physiological provocative maneuvers. The second and third phases were performed in three patients from each group with sensor activity On and Off. In group I, heart rate changed during tilt only in the DDDR mode. In group II, heart rate changes were comparable in both modes. Catecholamine levels in group I were higher during DDDC than during DDDR pacing (P < 0.05). In group I, heart rate did not change during phases II and IV of the Valsalva maneuver in the DDDC mode, but behaved nearly physiologically after sensor activation. A late and a paradoxical response to nitroglycerin was observed in groups I and II and to phenylephrine in group I. During physiological maneuvers, significantly greater variations in heart rate were observed during DDDR than during DDDC pacing. Sympathetic SDP provides physiological modulations of the heart rate were provided by a sympathetically driven pacing system in patients with AV block and CI.

Redox potential measurements of the Mycobacterium tuberculosis heme protein KatG and the isoniazid-resistant enzyme KatG(S315T): insights into isoniazid activation

Mycobacterium tuberculosis KatG is a multifunctional heme enzyme responsible for activation of the antibiotic isoniazid. A KatG(S315T) point mutation is found in >50% of isoniazid-resistant clinical isolates. Since isoniazid activation is thought to involve an oxidation reaction, the redox potential of KatG was determined using cyclic voltammetry, square wave voltammetry, and spectroelectrochemical titrations. Isoniazid activation may proceed via a cytochrome P450-like mechanism. Therefore, the possibility that substrate binding by KatG leads to an increase in the heme redox potential and the possibility that KatG(S315T) confers isoniazid resistance by altering the redox potential were examined. Effects of the heme spin state on the reduction potentials of KatG and KatG(S315T) were also determined. Assessment of the Fe(3+)/Fe(2+) couple gave a midpoint potential of ca. -50 mV for both KatG and KatG(S315T). In contrast to cytochrome P450s, addition of substrate had no significant effect on either the KatG or KatG(S315T) redox potential. Conversion of the heme to a low-spin configuration resulted in a -150 to -200 mV shift of the KatG and KatG(S315T) redox potentials. These results suggest that isoniazid resistance conferred by KatG(S315T) is not mediated through changes in the heme redox potential. The redox potentials of isoniazid were also determined using cyclic and square wave voltammetry, and the results provide evidence that the ferric KatG and KatG(S315T) midpoint potentials are too low to promote isoniazid oxidation without formation of a high-valent enzyme intermediate such as compounds I and II or oxyferrous KatG.

Endosonography in the diagnosis of "blue rubber bleb nevus syndrome": an uncommon cause of gastrointestinal tract bleeding

Blue rubber bleb nevus syndrome is a rare condition characterized by the presence of multiple angiomatic lesions of the skin. These are associated with similar lesions in other organs, namely in the gastrointestinal tract, causing anemia through chronic bleeding. We describe the case of a 72-year-old woman with microcytic anemia. A barium study revealed irregular lacunae in the distal esophagus. A subsequent endoscopy showed blue nodular lesions similar to angiomas of the esophagus and stomach fundus. Endosonography confirmed its angiomatic nature. Exploration of other organs, using magnetic resonance and cranial computed tomography, did not reveal the presence of this type of lesion. In physical examination, two angiomatic lesions were observed on the face and lips, respectively. These were blue in color and compressible, leaving an empty wrinkled sac that rapidly refilled, typical of angiomas.

Tuberculosis surveillance and evaluation system in Portugal

Tuberculosis is an important public health problem in Portugal, so a new and improved computerized programme for the surveillance and evaluation of tuberculosis data was set up to obtain more precise information of relevant epidemiological indices, besides helping clinicians and regional coordinators to evaluate the local situation, such as clinical features, results of treatment and surveillance of failures and abscondings. Data stored on the computer is described in detail. The evolution of the incidence of tuberculosis is presented, together with more detailed figures for 1990. These figures were obtained with the former, cruder process. The present system is now being deployed and checked, after 1 year's trial and evaluation by some of its users. Its results will be presented in a future publication.

Genetic polymorphism of red cell membrane band 3 in Japanese Brazilians

Limited proteolysis of intact red cells has been shown to yield peptides of 60 kDa and, in some individuals, 63 kDa, from the band-3 membrane protein. In a random population sample of 117 Brazilians of Japanese origin, the allele frequencies of the band-3 variants were p60 = 0.889 +/- 0.0205 and p63 = 0.111 +/- 0.0205. The phenotype frequencies fit the Hardy-Weinberg equilibrium for the hypothesis of three phenotypes controlled by two codominant alleles of a single autosomal locus. The frequencies of the alleles in this population of Japanese ancestry are highly different from those of Brazilian Caucasoid blood donors but rather similar to those of Brazilian Negroid donors.